Explained the technique to isolate and identity diseases causing pathogens. Isolate the organism out of the infected organism. Then grow it and innoculate that another host with that same bacteria and should cause the same illness.

Ignaz Philipp Semmelweis

1818-1865. Discovered the importance of handwashing but never got recognition for his attempt to apply these techniques developing medical practices.

Paul Ehrlich

1910 Discovered first medical antibiotic agent. arsinic based Salvarsan which was used to treat Syphilis

Alexander Fleming

1928 Discovered penicillin. Wasnt mass produced until WWII (1942) to prevent soliders from dying from infections. This was the start of the antibiotic era.

Illnesses caused by Staphococcus aureus.

Pneumonia. Endocartitis. Food poisoning. Wound infections

Saprophyte vs commensal vs parasite

Saprophyte lives on dead organic material. Commensal organism that lives in or on another organism with one befitting the other other having no effect.. parasite one organism benefits the other is harmed. Normally talking about Eukaryote parasites

Saprophyte

Is an organism that is growing on dead organic material

True pathogen vs opportunistic pathogen

True Pathogen is a disease causing organism. Opportunistic pathogen does not normally cause disease but under certain conditions it can cause disease.

Exogenous vs endogenous infection

Exogenous is an infection caused from an outside organism (ex. fomite. soil. etc). Endogenous infection is coming from an opportunistic infection (normal flora or latent infection).

Colonization vs disease

Colonization is an infection in which the organism is growing but does not causes symptoms. Disease is where the growth of the bacteria causes infection.

MRSA

is resistant to methicillin and all the drugs similar to this. (1960)

outcomes when a microbe infects a host

1. Transient colonization: infection comes in and tries to take hold but only lasts a short period of time. 2. Long-term symbiosis: Where the infection takes hold and stays in for a long time (ex. bacteria in gut) 3. Disease: the microbe comes in and colonizes and causes infection and harm to the host

Very small peptidoglycan layer. Has an outer membrane with lipopolysaccharides (LPS can be used for identification) attached to it. Contains pores (porins). Has a periplasmic space. Direct linking between animo acids in cell wall.

Transfromation: uptake of genetic material by competent cell. Conjugation uptake of foreign DNA by pilus. Transduction: use of a transducing phage. Can take place between species

Antibotic resistance are located

Located on plasmid of bacteria. Can be passed via transformation or conjugation.

Colonization of sterile sites in the healthy individuals

Colonization of one these sites generally involves a defect or breach in the natural defenses that creates a portal of entry

Resident Biota

The human as a habitat. Cell for cell microbes on the human body outnumber human cells at least ten to tone. Normal (resident) biota. Metagenoic being used to identify the microbial profile inside and on humans. Human microbiome project.

Acquring Resident Biota

The body provies a wide range of habitats and supports a wide range of microbes

Diverse population of microbes. Varies due to hormone levels. The vaginal microbiota affects the health of women and impacts the success of pregnancy. Vagina hosts unique consortia of microbes suggesting selection for these key organisms

Bacterial Vaginosis

BV. Is a condition linked to numerous health including. The most prevalent cause of vaginal symptoms among women of childbearing age. About 4 million visits in US. High rate of relapse cause is unknown. Normally contains few types lactobacillus. During BV contains a greater diversity of morphotypes and clue cells. INCREASES RICHNESS AND DIVERSITY OF MICROBES. Treatment with antibiotics result in a rapid decline of anaerobic bacteria.

Skin microbes and habitat

Is transiently colonized. Mostly gram positive bacteria.

Virulence

The degree of pathnogenicty. Determined by its ability to establish itself in the host and cause damage. Different healthy individual share widely varying responses to the same microorganism. host evolve.

Virulence factors (ones that aid in virulence)

Any characteristic or structure of the microbe that contributes to its virulence. Adhesins. 1.Invasins. 2. Toxins. 3. Byproduct of growth. 4. Mechanisms to evade immune response. 5. Ability to grow intracellularly.

E. coli remain extracellular and induce the formation of pedestals on the host cell surface. Help them to stick on hold onto the cell.

Surface cell adhesion

Salmonella typhirum. Have surface cell adhesions. Enter the epithelia cells and can be taken up by macrophages. Inside the phage can live and grow within the vacuole. Allows transport and a growth environment of the microbe.

Hyaluronidase

Digests hyaluronic acid that holds cells together. S. pyogenes

Coagulase

Contributes to clotting of blood. Wall of protection form immune defesnes. S. aureus

Streptokinase

Disssolve blood clooting. Free themselves from blood clots so they can spread.

Part of the bacterial cell. A componenet of the outher membrane of Gram negative bacteria. Ex. LPS (lipopolysaccharides) . Also known as lipid A. Heat stable. Relatively less toxic. Not convertible to toxoids. Poor neutralized by antibodies. Siilar toxicites for most tissues and cells low blood pressure and raised temperature. may cause endotoxic shock. generalized organ failure. intravascular coagulation and death.

Toxin

Any substance that is poisonous to other organism. According to hwo the toxins are released from the bacterial cells endo/exo toxins.

Exotoxins

Specific to a particular bacterial species that produces the disease associated with the toxin. Clostridium tetani produces tetanus toxin. Viruulent strains produce toxins while avirulent strains do not. Toxin is the major determination of virulence. Produced by both Gram positive and Gram negative bacteria. Usually secreted and are proteins. Highly toxic in very low concentrations

Produced by Corynebacterium diptheriae. Very potent in its action. AB toxin. B is binding part of toxin. A subunit is lethal single diphteria bacillus can produce 5000 molecules per hour. INTERRUPTS PEPTIDE FORMATION AT THE RIBOSOMAL LEVEL.

Exotoxins produced by many bacteria like Streptococci or Staphylococci. Destroy neutrophils and macrophages. More effective when released by microbes engulfed by neutrophil. Count of WBC decrease

Leukostatin

Exotoxins interferes with teh ability of leukocytes to engulf microrganisms that secrete the exotoxin.

Toxemia

The spreading of exotoxins by blood from the site of infection. Some diseases caused due to ingestion of preformed toxins. Called intoxications. Foodborne botulism. Neurotoxin that causes a flaccid paralyis where muscles go limp.